Vinyl acetate

108-05-4

Hazard Summary-Created in April 1992; Revised in January 2000

Vinyl acetate is primarily used as a monomer in the production of polyvinyl
acetate and polyvinyl alcohol. Acute (short-term) inhalation exposure
of workers to vinyl acetate has resulted in eye irritation and upper respiratory
tract irritation. Chronic (long-term) occupational exposure did
not result in any severe adverse effects in workers; some instances of
upper respiratory tract irritation, cough, and/or hoarseness were reported.
Nasal epithelial lesions and irritation and inflammation of the respiratory
tract were observed in mice and rats chronically exposed by inhalation.
No information is available on the reproductive, developmental, or carcinogenic
effects of vinyl acetate in humans. An increased incidence of nasal
cavity tumors has been observed in rats exposed by inhalation. In
one drinking water study, an increased incidence of tumors was reported
in rats. EPA has not classified vinyl acetate for carcinogenicity.

Uses

Vinyl acetate is primarily used as a monomer in the production of
polyvinyl acetate and polyvinyl alcohol. (1)

Vinyl acetate is also used as a raw material in the production of
other chemicals, in adhesives, water-based paints, nonwoven textile
fibers, textile sizings and finishes, paper coatings, inks, films, and
lacquers. (1,2)

Sources and Potential Exposure

Exposure is most likely to occur in the workplace, where individuals
may be occupationally exposed to vinyl acetate via inhalation or dermal
contact during its manufacture or use. (1)

Exposure may also occur through the inhalation of ambient air in
the vicinity of facilities that manufacture or use this compound. (1)

Assessing Personal Exposure

No medical test is currently available to measure vinyl acetate in
the blood, urine, or body tissues. Measurement of metabolites
are not useful for showing whether exposure has occurred. (1)

Chronic occupational exposure did not result in any severe adverse
effects in workers. Some instances of upper respiratory tract
irritation, cough, and/or hoarseness were reported. (1,2)

Nasal epithelial lesions and irritation and inflammation of the respiratory
tract were observed in mice and rats chronically exposed by inhalation.
(1,2,5)

The Reference Concentration (RfC)
for vinyl acetate is 0.2 milligrams per cubic meter (mg/m3)
based on nasal epithelial lesions in rats and mice. The RfC
is an estimate (with uncertainty spanning perhaps an order of magnitude)
of a continuous inhalation exposure to the human population (including
sensitive subgroups) that is likely to be without appreciable risk of
deleterious noncancer effects during a lifetime. It is not a direct
estimator of risk but rather a reference point to gauge the potential
effects. At exposures increasingly greater than the RfC,
the potential for adverse health effects increases. Lifetime exposure
above the RfC does not imply
that an adverse health effect would necessarily occur. (2)

EPA has high confidence in the study on which the RfC
was based because it identified both a no-observed-adverse-effect level
(NOAEL) and a lowest-observed-adverse-effect
level (LOAEL) for histopathology
of the nasal olfactory epithelia in rats and mice in a chronic 2-year
study, used an adequate number of animals, and was thorough in reporting
experimental and exposure details; high confidence in the database because
it provides sufficient supporting data for the RfC;
and, consequently, high confidence in the RfC.
(2)

EPA has calculated a provisional Reference Dose (RfD)
for vinyl acetate of 1.0 milligrams per kilogram body weight per day
(mg/kg/day) based on altered body and kidney weights in rats. The provisional
RfD is a value that has had some form of Agency review, but it does
not appear on IRIS. (9)

Reproductive/Developmental Effects:

No information is available on the reproductive or developmental
effects of vinyl acetate on humans.

In one study, reduced body weight gain was reported in rats exposed
to high levels of vinyl acetate by inhalation. Fetal growth retardation
occurred at the highest exposure level but may have been due to the
marked reduction in maternal body weight gain and not to a direct developmental
effect of vinyl acetate on the fetus. Minor skeletal fetal defects/variants
were also observed at the highest exposure level, but these effects
may have been secondary to maternal toxicity. (1,2)

Reduced body weight gain was reported in study of rats exposed to
vinyl acetate in their drinking water; no effects on reproductive performance
were noted. (1,2)

Cancer Risk:

No information is available on the carcinogenic effects of vinyl
acetate in humans.

An increased incidence of nasal cavity tumors has been observed in
rats exposed by inhalation, but not mice. (1)

In rats exposed to vinyl acetate in drinking water, an increased
tumor incidence (including neoplastic nodules of the liver, adenocarcinomas
of the uterus [in females], and C-cell adenomas or carcinomas of the
thyroid) was reported. However, there are many limitations to
this study. (1,5)

In another drinking water study, no treatment-related tumors were
observed in rats. (1)

EPA has not classified vinyl acetate as to its possible human carcinogenicity.
(2)

Physical Properties

The chemical formula for vinyl acetate is C4H6O2,
and its molecular weight is 86.09 g/mol. (1)

Health Data from Inhalation Exposure

AIHA ERPG--American Industrial Hygiene Association's emergency
response planning guidelines. ERPG 1 is the maximum airborne concentration
below which it is believed nearly all individuals could be exposed up
to one hour without experiencing other than mild transient adverse health
effects or perceiving a clearly defined objectionable odor; ERPG 2 is
the maximum airborne concentration below which it is believed nearly all
individuals could be exposed up to one hour without experiencing or developing
irreversible or other serious health effects that could impair their abilities
to take protective action. ACGIH ceiling--American Conference of Governmental and Industrial
Hygienists' threshold limit value ceiling; the concentration of a substance
that should not be exceeded during any part of the working exposure. ACGIH TLV--ACGIH's threshold limit value expressed as a time-weighted
average; the concentration of a substance to which most workers can be
exposed without adverse effects. LC50 (Lethal Concentration50)--A calculated
concentration of a chemical in air to which exposure for a specific length
of time is expected to cause death in 50% of a defined experimental animal
population. LOAEL--Lowest-observed-adverse-effect level. NIOSH ceiling--National Institute of Occupational Safety and Health's
recommended exposure limit ceiling; the concentration that should not
be exceeded at any time. NOAEL--No-observed-adverse-effect level.

The health and regulatory values cited in this factsheet were obtained
in December 1999.aHealth numbers are toxicological numbers
from animal testing or risk assessment values developed by EPA. bRegulatory numbers are values that have been
incorporated in Government regulations, while advisory numbers are nonregulatory
values provided by the Government or other groups as advice. NIOSH, ACGIH,
and AIHA numbers are advisory.cThe LOAEL and NOAEL are from the critical
study used as the basis for the EPA RfC.

International Agency for Research on Cancer (IARC).
IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals
to Humans: Some Chemicals Used in Plastics and Elastomers. Volume
39. World Health Organization, Lyon. 1986.

National Institute for Occupational Safety and
Health (NIOSH). Pocket
Guide to Chemical Hazards. U.S. Department of Health and
Human Services, Public Health Service, Centers for Disease Control and
Prevention. Cincinnati, OH. 1997.